MEGATRONICS V3.0 QUICK START GUIDE Thank you for purchasing the Megatronics v3.0! This small guide will answer the basic questions on how to connect the board to your 3D printer. For more information visit the Megatronics product page http://reprapworld.com/?products_details&products_id=468. ReprapWorld.com may provide updates to the firmware, documentation and specifications. Please refer to the product page for the latest information. Safety warnings Do not exceed the recommended voltage (24V) for the board on the power supply (high power) input. This may cause permanent damage to the board. The 5V circuit is protected from shorts by a resettable 500mA fuse. The high power inputs are protected by a NON-resettable fuse. Shorting the high power circuit may cause the SMD fuses to burn out, requiring replacing the fuses. Do not unplug stepper motors from the board while powered. This may cause the stepper drivers to be damaged permanently and/or damage the board permanently. Do not modify anything while the board is powered, always remove the USB cable and power off the power supply before modifying anything. Features The Megatronics board is designed to be the most advanced electronics board, with many out-of-the-box functionality on-board. You can use this board in all types of 3D-printers in the consumer market today. Amongst others, these are the major features: Atmega2560 Powerful Atmega2560 processor with 256 kb memory, running at 16Mhz Thermocouple On-board support for connecting two thermo couples and two external SD Card Autonomous printing from Micro SD card on board or an external SD card upgrade option. Six MOSFETs The board has 3 regular MOSFETs (25A), two small MOSFETs for fans, and one MOSFET for the heated bed (IRLS3034PBF) to support many needs. Up to 6 stepper drivers Compatible with RAMPS, 6 slots for stepper drivers (not included). Modularized to make replacement easy. Support for many peripherals The board's functions can be easily extended with LCD, keypad etc. See the connectors section for more information Copyright 2014, Reprapworld.com - 1
Required software We provide software on our website to help you out. This software is modified to support our hardware out-of-the-box. See the section 'software downloads' for the latest version of the software. Preparing the board The board is supplied with a Marlin firmware. Because of the continued development and your specific needs, changes are you want to upload another firmware. If you didn't download our supplied Arduino version, you need to modify it. You can use Arduino IDE to upload firmware to the Megatronics board. Under Linux select as board 'Arduino Mega 2560 or Mega ADK'. Under other operating systems the USB will not be reset correctly and you will need to adjust the boards.txt. This file is located in <Arduino directory>/hardware/arduino/boards.txt. Add the following text to the file: megatronics.name=megatronics megatronics.upload.protocol=wiring megatronics.upload.maximum_size=258048 megatronics.upload.speed=115200 megatronics.bootloader.low_fuses=0xff megatronics.bootloader.high_fuses=0xda megatronics.bootloader.extended_fuses=0xf5 megatronics.bootloader.path=stk500v2 megatronics.bootloader.file=stk500boot_v2_mega2560.hex megatronics.bootloader.unlock_bits=0x3f megatronics.bootloader.lock_bits=0x0f megatronics.build.mcu=atmega2560 megatronics.build.f_cpu=16000000l megatronics.build.core=arduino megatronics.build.variant=mega Restart Arduino IDE and select Megatronics as board. You should be able to upload correctly now. While uploading the blue LED is lit and the RX/TX LEDs will blink fast. Testing the board To test the functionality of the board, a test firmware is available from the Megatronics poduct page. This firmware will help you test the board. Disconnect everything except the USB cable to your computer. Upload the the test firmware to the board with Arduino, the blue debug LED should blink every second. By using the serial monitor in Arduino the board will provide an output like: T1 1023 T2 1023 T3 1023 TC1 700 TC2 700 These values represent the resistance measured from t1 to t3 and thermo couple 1 & 2. When you connect a thermistor to the pins, the corresponding value in the serial monitor should change to about 890. By connecting the 12V lines, the MOSFETs should have power and their LEDs will blink in order. This verifies the MOSFETs and 12V power are OK. Also the stepper motors should turn when connected, with the 12V lines and stepper drivers in place. They will turn a short time and switch direction. These three tests will verify the basic functionality of the board. Copyright 2014, Reprapworld.com - 2
Plugging in the stepper drivers Most importantly you need to look at the correct orientation of the stepper driver. Plugging it the wrong way may cause permanent damage to the stepper driver and/or the Megatronics board. On the back of the stepper driver pcb should be a description of thee pin layout. Determine the vmot pin and layout the board to match the following pin definition: ENABLE M0 M1 M2 STEP DIR VMOT GND B2 B1 A2 A1 5V GND Disable/enable stepper Microstep setting 1/3 Microstep setting 2/3 Microstep setting 3/3 Step pulses Direction High power input (supply voltage) Coil 2 Coil 2 Coil 1 Coil 1 +5V Setting the microstepping can be down using the jumpers. Refer to the stepper driver documentation on how to set the jumpers. Copyright 2014, Reprapworld.com - 3
Quick Start This paragraph will show you how to connect the board. This is just a basic example, your requirements may differ. There is a lot of community support available in the RepRap forums http://forums.reprap.org. By placing your questions there other users may benefit of the information too. First connect your computer with a standard USB cable. The power LED should light up and the blue debug LED should blink once. The rxd and txd LEDs near the USB connector may blink fast for a short period. Put the stepper drivers in the slots, and connect the stepper motors. You can connect up to 7 stepper motors, 1 for each axis, except for the Z-axis, which allows two stepper motors to be Copyright 2014, Reprapworld.com - 4
connected. The power supply should be connected to the power screw terminals. Mind the polarization, the yellow wires should be +. Connect the heated bed to HB, this terminal allows larger currents, up to 14A. The first extruder heater should be connected to E1. A second extruder can be connected to E2. Fans can be connected to the fan1 and fan2 terminals. You can easily connect end stops to the board. There is support for 6 end stops (3 min, 3 max). For opto end stops you will need the S(ignal), - and + pins. For mechanical end stops the S(ignal) and pins are sufficient. The thermistors for reading heated bed and extruder temperature can be connected to the thermistor pins. Polarization is not an issue here. Advanced usage Connecting a second or third extruder You can hook up another extruder using the applicable stepper driver slots, temperature reading pins and power terminals. Hooking up an external stepper driver ReprapWorld.com provides external stepper drivers to enable you to run multiple stepper drivers on one axis. Refer to the external stepper driver documentation for more information. Warranty We provide a three months limited warranty on the board. You should verify the proper function of the board when it arrives, you may use the test firmware as described in the paragraph 'Testing the board'. When you have determined that the board is not functioning properly, please provide a detailed description of the problem including pictures (if applicable) to info@reprapworld.com. Make sure to include your order number. Feedback We love to hear feedback from our users. This way we can keep our boards the best option for the RepRap community. If you have ideas or comments, please feel free to drop an email to info@reprapworld.com. Copyright 2014, Reprapworld.com - 5